The Effect of protease (subtilisin Carlsberg) on the removal of hemoglobin as protein soil was studied. The hydrolysis characteristics of subtilisin Carlsberg was examined by electrophoretic techniques. The fragmentation patterns of hemoglobin were analyzed by SDS-PAGE. The hydrolysis efficiency was evaluated by analysis of protein bands shown on gels before and after hydrolysis by using densitometer. 1. The hydrolysis of hemoglobin by subtilisin Carlsberg was increased markedly with the increase of the enzyme concentration. 2. The hydrolysis of hemoglobin by subtilisin Carlsberg was effectively increased in proportion to increasing of the hemoglobin concentration up to a certain point, but it began to decrease above the point. 3. The hydrolysis of hemoglobin by subtilisin Carlsberg followed the first order kinetics, yielding a rate constant of $4.05 ime10^{-4}S^{-1}s$. 4. The hydrolysis of hemoglobin by subtilisin Carlsberg was highest at $50^{circ}C$ and was decreased markedly at $80^{circ}C$. 5. The hydrolysis of hemoglobin was comparatively low at pH 7.0~8.0, and highest at pH 11.0.